10 Rules of Gorgeous Hair Color

1. Do Your Prep Work

Split ends look even split-end-ier with highlights, so get a trim before you color. It's also best to wash your hair the night before coloring—hair that's too clean or too dirty can mess with how the color turns out. And if you're going to a salon, wear your hair as you normally do so the colorist can get an accurate sense of your style.

2. Know Yourself

Dorky as it may sound, you have to be yourself when it comes to hair color. If you're fair, don't look at Salma Hayek for inspiration. And if you're olive-tone, you will never pull off Scarlett Johansson blonde, no matter how much bleach you pour on. Pale and pinkish skin look best with blonde or light brown hair, while those who have medium or dark skin with yellow or golden undertones should go for more coppery auburns and dark browns.

Your hair's texture is also a factor. As a general rule, wavy hair can handle up to five or six shades of color, but if your hair is pin-straight, stick to more uniform color—highlights will look very obvious.

4. Wrap It Up

After you've applied the color, cover your hair with plastic wrap, Gloria Swanson-style (a shower cap works well, too). Not only does this help the color penetrate better, but it prevents goop from streaking your forehead—and the bathroom sink.

5. Learn How to Communicate

The most reliable way to make your hair-color wishes clear at the salon is to bring in a picture of what you're envisioning. But understand that's just a jumping-off point—your colorist will (and should) tailor the color to your complexion. And unless you've got a cosmetology degree, it's not a good idea to use salon jargon. Do away with the "caramel" this and the "buttery" that. Instead, describe what you want as if you were telling a friend ("natural-looking highlights that aren't too stripey," for example).

6. Take It Easy

Like a Spinning class or a new relationship, blonde hair works better if you baby-step your way into it. If you go from Michelle Obama brunette to Donatella blonde overnight, you will destroy your hair. Don't go more than two shades lighter in base color or four to five in highlights in one sitting. Achieving a pretty shade of blonde usually takes anywhere from four to six sessions. More than that could burn your hair—and burned hair looks like crap in any color.

7. Fix It Up

If you were hoping for strawberry blonde but ended up flaming scarlet, you can mute the color by slathering on a deep conditioner while hair is damp, then covering it with plastic wrap and a hot towel. (Try Neutrogena Triple Moisture Deep Recovery Hair Mask.) After ten minutes, remove the towel and the plastic wrap, blast your head with a blow-dryer, leave the mask on for another ten, and then shampoo and condition. If the color still sucks, see a pro.

8. Avoid Bad Things

Hair has vices, too. They are: overzealous heat styling, chlorine, excessive washing, and the sun. (Imagine how great your highlights would look if only you lived in an igloo.) If your hair turns green or brassy, wash with a purple-tinted shampoo once a week. (The pros all recommend Clairol Professional Shimmer Lights Shampoo.) And prevent future damage by coating hair in conditioner before you go to the beach or pool.

9. Prolong the Results

You know how your hair is all gorgeous and glossy and actually looks like the girl on the box right after it's colored? Well, there are ways to keep the shine going. As obvious as it sounds, use color-protecting shampoo (we like Kiehl's Sunflower Color Preserving Shampoo) and don't skip conditioner. Hair that's moisturized reflects light better. Also, be sure to use styling products with silicone (try a serum, likeKérastase Nutritive Serum Oléo-Relax, when hair is damp, then air- or blow-dry).

10. Deal with the Gray

It starts innocently enough: One minute you're plucking an errant silver strand at your temple, and the next, you've locked yourself in the bathroom, eyes tearing up as you yank out more of them than you can count. Before the situation gets out of hand, try a semipermanent dye (which will cover grays) all over your hair. It's gentle and washes out gradually, so you don't end up with obvious roots. To cover grays between coloring sessions, use a temporary tool that deposits liquid color. ColorMark is a lip-gloss-like wand you can use on single strands; for larger patches, try TouchBack Temporary Hair Color Marker, which has a thick tip that allows you to draw it on like a marker (both wash out with shampoo).